Re: [PATCH net] net: mana: Set 1 usec / 1 comp as default and minimum interrupt moderation

[sashiko-bot@kernel.org]

> From: Haiyang Zhang <haiyangz@microsoft.com>
> 
> The existing code sets interrupt moderation defaults to 0 usec and 0
> completions, which may cause CQ starvation of our NIC HW, and TX time
> out error like:
> mana 7870:00:00.0 ens1: NETDEV WATCHDOG: CPU: 14: transmit queue 4 timed out 63434 ms
> 
> To fix, change the default and minimal rx/tx usecs and frames to 1.
> When the HW supports interrupt moderation, reject ethtool rx/tx usecs
> and frames below 1.
> Also clamp the values written by mana_gd_ring_dim() to [1, max], so
> no caller, including the DIM work, programs a zero value.
> On the HW without interrupt moderation support, do not request CQ
> moderation, the usecs and frames stay at 0, and cannot be modified by
> ethtool.
> The PF capability is queried again when the device resumes from a
> reset or suspend, so re-initialize these settings before re-attaching
> the vPorts.
> 
> Advertise this change to the PF with the new driver capability flag
> GDMA_DRV_CAP_FLAG_1_SET_MIN_INTR_MOD_VALUE.
> 
> Cc: stable@vger.kernel.org
> Fixes: 433f482add31 ("net: mana: Add Interrupt Moderation support")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Sashiko has reviewed this patch and found no issues.

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